Development of Time-spectroscopy System for Observing Internal-conversion Electrons at Rare Nuclear Excitation Phenomena

罕见核激发现象中内转换电子观测时间谱系统的研制

• 批准号: 09650073
• 负责人: KISHIMOTO Shunji
• 金额: $ 1.86万
• 依托单位: High Energy Accelerator Research Organization
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09650073/
• 关键词: Nuclear Excitation; Synchrotron Radiation; X-ray; electron Analyzer; Avalanche Photodiode; Internal-conversion Electrons; Time-spectroscopy; 放射光X線; アパランシェ.フォトダイオード; 内部転換電子線

In FY1997, an electron analyzer for time-spectroscopy was designed and assembled. The analyzer was cylindrical-mirror type. Next year, some avalanche photodiodes (APDs) were tested at beamline BL14A of the Photon Factory. One device that had a thin SiOィイD22ィエD2 layer was chosen as the electron detector for the analyzer. Until the end of FY1998, we could not report the results of this project due to the delay of improving the electron analyzer and due to no chances of experiments at Spring-8. However, in April and May of 1999, we were able to execute the experiments under a new project of the SPring-8. In the experiments, we successfully observed the nuclear excitation by electron transition (NEET) in 197Au. The internal-conversion electrons emitted from excited nuclei were directly detected by the APD device without the electron analyzer. This method was adopted for taking a larger efficiency of the conversion electrons. The observed NEET probability was close to the calculated value (E.V.Tkalya, JETP 78,239(1994)), though smaller by three orders of magnitude than the previous experimental value (H.Fujioka et al., Z.Phys. A315, 121 (1984)).

1997财年，设计并组装了时间光谱电子分析仪。分析仪为柱面镜型。明年，一些雪崩光电二极管 (APD) 在光子工厂的光束线 BL14A 上进行了测试。选择具有薄 SiOiD22ィD2 层的一种装置作为分析仪的电子探测器。直到1998财年末，由于电子分析仪改进的延迟以及Spring-8没有机会进行实验，我们无法报告该项目的结果。然而，在1999年4月和5月，我们能够在SPring-8的新项目下进行实验。在实验中，我们成功地观察到了197Au的电子跃迁核激发（NEET）。 APD装置直接检测激发核发射的内转换电子，无需电子分析仪。采用这种方法是为了获得更大的转换电子效率。观察到的 NEET 概率接近计算值（E.V.Tkalya，JETP 78,239（1994）），尽管比之前的实验值小三个数量级（H.Fujioka 等人，Z.Phys.A315, 121（1984））。

项目成果

S. Kishimoto: "Observation of Nuclear Excitation in ィイD1197ィエD1 Au with an APD electron detector"Spring-8 User Experiment Report. No. 3 (1999A). 104-104

S. Kishimoto：“使用 APD 电子探测器观察 D1197 Au 的核激发”Spring-8 用户实验报告第 3 号（1999A）。

S. Kishimoto: "Electron Time-spectrosecopy system for observing nuclear Excitation on ィイD1169ィエD1 Tm"Photon Factory Activity Report 1998/. #16, Part B. 290-290 (1999)

S. Kishimoto：“用于观察光子工厂活动报告核激发的电子时间光谱系统 1998/。16，B 部分。290-290 (1999)

S.Kishimoto: "Observation of Nuclear Excitation ^<197>Au with an APD electron detector"SPring-8 User Experiment Report. No.3(1999A). 104 (1999)

S.Kishimoto：“用 APD 电子探测器观察核激发 ^<197>Au”SPring-8 用户实验报告。

S.Kishimoto: "Observation of Nuclear Excitation by Electron transition(NEET)in ^<197>Au with a Silicon APD detector"SPring-8 Reseach Frontiers 1998/1999. (to be published). (2000)

S.Kishimoto：“用硅 APD 探测器观察 ^<197>Au 中电子跃迁 (NEET) 的核激发”SPring-8 研究前沿 1998/1999。

S.Kishimoto: "Observation of Nuclear Excitation by Electron transition(NEET)in ^<197>Au with Synchrotron X-rays and a Silicon APD detector"Submitted to Physical Review Letters. (2000)

S.Kishimoto：“用同步加速器 X 射线和硅 APD 探测器观察 ^<197>Au 中电子跃迁 (NEET) 的核激发”，提交给《物理评论快报》。